Fall 2003 eMOLT Update

The Northeast Consortium-funded "Environmental Monitors on Lobster Traps Program"  has expanded this year.   The temperature probes that were deployed during the intitial phase of the project are still in the water and continue to record hourly values at dozens of locations throughout the Gulf of Maine and  the Southern New England Shelf.  This aspect of the project has been the most successful given now three full years of data at several locations.  Lobstermen have been very cooperative and show no loss of interest.  Most of the 2003 observations will be downloaded in early 2004 and, based on the few that have come it as of this writing, will provide solid evidence for the unusally cold year. Given the relative simplicity,  the small cost of the operation, and the potential for funding from other sources,  we hope to maintain this routine for years to come.

Subsequent NEC funding, however, provided additional instrumentation for detecting salinity and current velocity.  The salinity probes were deployed by several lobstermen at sites ranging from southern end of the Great South Channel to the Grand Manan Channel and all but one have already returned at least one multi-month record.  More time series will be downloaded when these units are  collected at the end of this year.   As usually happens with this kind of monitoring program, some interesting events have appeared from time to time in the record that deviate from the traditional  understanding of slow seasonal changes.  The episodic nature of these events poses questions about the driving forces that regulate the natural variability.  One hypothesis that has arisen, for example, is the possible existence of submarine freshwater discharges off the coast of Maine.  Stay tuned for the results of further investigations, observations, and analysis of salinity records in the following year. 

However, the most exciting new phase of eMOLT is the drifter deployments to measure current velocity.  As discussed in recent eMOLT updates, the pilot project in  June 2003 went well.  All 19 units deployed off Isle of Haut  were subsequently reported at least once with 55 reports in all.  Six of  the eight satellite-tracked units were recovered and usable next summer.  We are working with the marine science students at the Southern Maine Community College in the design, construction, and assembly of over 100 units for next summer.  Especially exciting is the designing/development of our own satellite-tracked unit for less than a quarter of the cost of the more traditional oceanographic equipment.  We have borrowed a technology from the trucking industry where we secure a self-contained GPS unit (<$400) to the top of the PVC-constructed "eMOLT drifter" which transmits its position to the satellite on a near-hourly basis.  Within minutes, this data point  (15 cents each)  is sent to Woods Hole where it is immediately and automatically posted on a website.  Stay tuned for the details of an extensive deployment throughout the summer of 2004.

The possibilities to develop this satellite technology further so as to transmit bottom temperatures from fixed buoys is also under investigation.  With a bit more engineering, we should be able to rig many of our participants in future years with bottom temperatures transmitted in realtime! We hope to test this operation in the coming months.

For further information contact: James.Manning@noaa.gov

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